Andrew Roberts, 42, and his son Mark Roberts, 23, threatened the guard with a handgun outside the Allied Irish Bank in London’s Finchley Road last October before making off with around GB pound 25,000 in cash.
The guard quickly alerted police, who gave chase.
Mark fired shots in the street in an attempt to get away, but was arrested later.
He was sentenced to a total of 15 years in jail, and his father will serve 18 years.
DS Neil Williamson of Finchley Flying Squad described the incident, which happened in broad daylight, as “a dangerous, audacious attempt to rob the security guard”.
“Mark Roberts fired shots in the street in his attempt to get away. He could easily have shot an innocent passer-by.
“The sentence today should send a stark message to those engaged in this type of criminality.”
